1. Field of the Invention
This invention relates, in general, to braking systems, and, more particularly, to regenerative braking systems for vehicles. This invention relates to a regenerative braking system that slows a vehicle by operatively connecting a hydraulic pump system to the vehicle's rotating wheels to pump fluid to a turbine for electric generation.
2. Related Art
The prior art is replete with approaches to extracting, storing and beneficially using the energy usually dissipated during vehicle braking. These approaches in part include many combinations and interconnections of flywheels, hydraulic and pneumatic accumulators, motors, pumps, and the like. None of the known prior art, however, incorporates a turbine generator for regenerative braking and electrical energy generation, as in the present invention. The following brief review of some of the prior art will be useful in establishing the novelty and utility of the present invention.
Bultmann (U.S. Pat. No. 4,114,734) has disclosed a braking system having a hydrodynamic coupling driven by the vehicle, wherein the operating fluid is conducted into an external circulatory system by way of a cooler or radiator. This hydrodynamic coupling also serves as a feed pump for the operating fluid and is operatively connected with a turbine to drive a separate cooling fan. In this manner, heat removal from the braking system may be facilitated.
Jerome (U.S. Pat. No. 4,282,948) discloses a motor vehicle propulsion system including a liquid-filled flywheel to store kinetic energy. When motor vehicle acceleration is desired, the flywheel liquid is coupled to a turbine which is connected through a drive train to drive the rear wheels.
Smitley (U.S. Pat. No. 4,342,371) also teaches a flywheel approach to storing and supplying energy for vehicles. The flywheel is selectively connected to the power train of a vehicle and absorbs energy from the vehicle's ground engaging wheels during the deceleration of the vehicle. This process provides at least a degree of vehicular braking. A clutch is also provided to selectively engage/disengage the flywheel connection to the wheels.
Chang (U.S. Pat. No. 4,798,053) employs a vehicle's engine to compress air when the vehicle decelerates and reuses the air thus-compressed to drive an air motor which assists in moving the vehicle when it is underway again.
Gray et al. (U.S. Pat. No. 5,505,527) provides a vehicular power train with regenerative braking having a pump/motor combination connected to the vehicle's drive wheels. In the vehicle's braking mode, the pump comes into play and charges an accumulator. When it is desired to accelerate the vehicle, the accumulator releases its stored energy by providing hydraulic power to the motor which, in turn, drives the vehicle's wheels. Controls and switches are provided to implement and coordinate the various functions of the components.
Ellis et al. (U.S. Pat. No. 5,931,249) disclose a kinetic energy storage system that uses a flywheel with a motor generator to store energy. The flywheel rotates at a high speed in a vacuum. The flywheel may also be used to power the vehicle.
Martin-Gerez (U.S. Pat. No. 6,068,351) teaches an axle-driven pumping mechanism used to pressurize a volume of hydraulic fluid in response to a braking command. The fluid thus-pressurized activates a turbine that is used to drive a cooling fan directed at a radiator used to dissipate heat in the hydraulic fluid.
Gardner, Jr. (U.S. Pat. No. 4,753,078) discloses an electro hydraulic vehicle drive system, and Bullock (U.S. Pat. No. 6,170,587) discloses a hybrid propulsion system for road vehicles.
Thus it is a primary objective of this invention to provide a braking system that generates electrical energy while facilitating braking of the vehicle. It is another object of this invention to include a turbine generator in such a system that is powered by a fluid-jet driven by the vehicle's wheels. It is a further object of this invention to store the generated electrical energy for the later use by the vehicle. Another object of this invention is to provide a turbine generator regenerative braking system that is applicable to any apparatus requiring braking independent of the primary motive power.